Is There a Best Time to Take Your Thyroid Medication?

Managing an underactive thyroid gland requires you to take a thyroid drug every single day. Consistency is key, meaning it's important to take your thyroid pill at the same time daily. Most are told to take their medication first thing in the morning, rather than before they go to sleep. But the truth is that either time of day works, although one time may better suit your lifestyle. In addition, there is some research suggesting that taking your dose at bedtime may allow for better thyroid hormone absorption.

Discuss when to take your thyroid medication with your doctor. These pros and cons can help guide your conversation.

Morning Levothyroxine

Taking your thyroid hormone replacement medication (most commonly, levothyroxine) first thing in the morning with water and waiting at least an hour before eating breakfast or drinking coffee is what has been traditionally recommended for years by thyroid experts.

In addition to waiting an hour before eating food or drinking coffee, experts also recommend waiting at least three to four hours before taking any other medications or supplements that may interfere with levothyroxine's absorption.

Pros

For many people, taking their thyroid medication in the morning is what they have always done.

  • Given the importance of consistency, the benefit of staying with a long-standing routine cannot be overlooked.

In this instance, switching to nighttime levothyroxine does not really make sense, unless your doctor is worried about medication absorption or interactions, which would be detected in your periodic thyroid-stimulating-hormone (TSH) blood test.

Cons

Some people find taking levothyroxine in the morning inconvenient and/or burdensome for the following reasons:

  • It may be difficult to wait an hour before eating or drinking coffee in the morning.
  • Other medications or supplements that can interfere with a thyroid drug's absorption, like a calcium or an iron pill, need to be taken in the morning.

Nighttime Levothyroxine

Similar to the morning levothyroxine guidelines, experts recommend waiting four hours after your last meal or snack before taking your nighttime thyroid medication.

Pros

Here are some potential pros to taking nighttime levothyroxine:

  • You don’t have to worry about when to eat breakfast.
  • It may be easier to avoid things that can interfere with thyroid medication absorption, such as calcium, iron, and high-fiber foods.
  • Coffee drinkers don't have to wait until an hour after their medication to enjoy their first cup.
  • Research suggests that levothyroxine may be better absorbed at night.

One study, reported in the Journal of Clinical Endocrinology and Metabolism, examined the impact on thyroid hormone blood tests after changing the timing of when levothyroxine was taken from early morning to bedtime.

In all the patients, TSH decreased and free thyroxine (T4) levels rose by changing thyroxine ingestion from early morning to bedtime. Triiodothyronine (T3) levels rose in all but one subject. 

Interestingly, TSH decreased irrespective of the starting TSH levels, suggesting better absorption of the thyroid medication when taken in the evening.

The researchers of this study suggested several explanations for the results:

  • Even when waiting for at least 30 minutes to eat, breakfast may be interfering with the intestinal absorption of levothyroxine. 
  • “Bowel motility is slower at night,” which means that it takes longer for the levothyroxine tablet to transit through the intestinal system. The increased transit time results in longer tablet exposure to the intestinal wall and therefore, better absorption and uptake of the medication.
  • The conversion process of T4 to T3 may be more effective in the evening.
when to take levothyroxine thyroid medication
​Illustration by Emily Roberts, Verywell

Cons

Taking your thyroid medication at nighttime may be challenging for the following reasons:

  • It's easy to forget to take your medication when you are tired.
  • You may have an inconsistent sleep schedule.
  • You may enjoy snacking prior to going to bed.
  • Thyroid drugs that contain T3 such as Cytomel and the natural desiccated thyroid drugs (Nature-throid and Armour Thyroid) have a slight stimulatory effect, which can make it difficult to sleep.

What Your Doctor May Recommend

If you do take a T3 drug, your doctor may recommend a time-released or sustained release formulation, or splitting your dose and taking your medication several times throughout the day. These approaches may minimize any sleep interference.

A Word From Verywell

In the end, the key to optimizing your thyroid health is to maintain consistency, taking your thyroid pill around the same time and in the same way each day.

With that, if you and your doctor decide to switch the timing of your thyroid medication, be sure to have your thyroid levels evaluated about six to eight weeks after you’ve made the switch.

Was this page helpful?
Article Sources